Method of manufacturing composite material structure

ABSTRACT

A seal member formed in a line shape having ends is inserted in a seal groove formed on at least one of adjacent side surfaces of segments. A lip portion is provided on a seal upper portion of the member so at least a tip end thereof projects to an outside of the seal groove when the member is inserted in the groove. The seal member is hollow or includes a concave portion on at least a seal bottom portion thereof. When assembling the segments as a single structure, the adjacent side surfaces of the segments are coupled to each other, and the seal member is crushed in a cross sectional direction by the side surface of the other segment to seal between the segments. With this, complication of manufacturing steps can be suppressed or avoided while realizing a satisfactory sealed state between the adjacent segments of a mold.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a hollowcomposite material structure. The present invention particularly relatesto a method of preferably manufacturing a composite material structurefor use as, for example, a fuselage of an aircraft by using a moldconstituted by a plurality of segments, the mold being kept as a singlestructure by coupling adjacent side surfaces of the segments to eachother.

BACKGROUND ART

In recent years, fiber-reinforced resin composite materials (hereinaftersuitably abbreviated as “composite materials”) are widely used in thefields in which metal materials have been conventionally used. Among thecomposite materials, carbon fiber reinforced materials formed byimpregnating carbon fibers as reinforced fibers with matrix resin suchas epoxy resin are lighter and stronger than the metal materials.Therefore, the carbon fiber reinforced materials are widely adopted inthe fields of sports goods, industrial machines, aerospace, and thelike.

In the field of aerospace among these fields, for example, stiffenedpanels formed by integrating skins and stiffeners made of the compositematerial are adopted in structures, such as wings and fuselages ofaircrafts. One of typical stiffeners is a stringer. Examples of themethod of integrating the stiffeners made of the composite material andthe skins made of the composite material include a co-curing method anda co-bonding method. According to the co-curing method, a plurality ofprepregs which become the stiffeners are laminated, and a plurality ofprepregs which become the skins are laminated. Then, these prepregs arecured by an autoclave to be integrally molded. According to theco-bonding method, after the stiffeners are first cured by theautoclave, a plurality of prepregs which become the skins are laminatedand cured by the autoclave to be integrally molded.

One example of the technology for manufacturing such structures of theaircrafts is a composite tool for molding a cylinder-shaped portion asdisclosed in PTL 1. In order to manufacture the cylinder-shaped portionmade of the composite material, the composite tool is configured by:arranging a plurality of (seven, for example) members or tiles in acylindrical manner; and coupling the members or tiles to one another.Seal units (seal members) are arranged at respective coupled portionseach between the members (tiles).

A specific example of the seal unit is an O-ring gasket that isexpandable. Grooves in which the O-ring gaskets are provided are locatedon respective side surfaces of the adjacent members (tiles) so as to bedisplaced from each other (so as to be alternately arranged), and theO-ring gaskets are arranged in these grooves. The O-ring gasket has ahollow structure (tubular structure) in a section thereof and isexpandable by a pressure difference generated during autoclaving.

The O-ring gasket seals between the adjacent members in a longitudinaldirection. Therefore, in PTL 1, in order to realize sealing at endportions of the adjacent members, a leak prevention insertion portion isprovided at the end portions. The insertion portion includes two holesfacing the groove at which the O-ring gasket is arranged. A part of theO-ring gasket is exposed to an outside through between the adjacentmembers. The exposed O-ring gasket is connected to a high-pressure airsource. With this, the O-ring gasket can be expanded by pressurizing aninside of the O-ring gasket.

According to PTL 1, in order not to weaken the structures of the members(tiles), the grooves are formed on the adjacent side surfaces of themembers so as to be provided alternately (so as to be displaced fromeach other). Further, since the O-ring gaskets are provided at thegrooves arranged as above, the O-ring gaskets are also provided so as tobe displaced from each other. Therefore, by the pressurization of theinside of the O-ring gasket by the high-pressure air source in additionto the pressure difference generated by the autoclave, the O-ring gasketarranged at one of the adjacent side surfaces of the members expands tocontact the other side surface, and the O-ring gasket arranged at theother side surface expands to contact the one side surface. With this,double seal is realized between the adjacent members.

CITATION LIST Patent Literature

PTL 1: Published Japanese Translation of PCT Application No. 2010-507504

SUMMARY OF INVENTION Technical Problem

However, according to the configuration disclosed in PTL 1, in order torealize a stable sealed state, various conditions need to beappropriately adjusted as below. Therefore, the method of manufacturingthe cylinder-shaped portion may become complex.

For example, the O-ring gasket disclosed in PTL 1 is a seal unit (sealmember) that is intended to expand. Therefore, in order to realize asatisfactory and stable sealed state, conditions of the autoclave needto be set to generate a preferred pressure difference, and shop air ofadequate pressure needs to be continuously supplied from an outsideduring the autoclaving.

Further, heat expansion of the O-ring gasket during the autoclavingneeds to be considered. For example, in order to realize a predeterminedexpansion coefficient in a cross sectional direction of the tubularstructure, a thermal expansion coefficient in the cross sectionaldirection needs to be considered in addition to the pressure differenceof the autoclave and the pressure of the shop air. Further, as describedabove, since the O-ring gasket is partially exposed from both endportions of the coupled portion, the amount of exposure is predicted toincrease by heat expansion in a line direction. Therefore, the O-ringgasket needs to be fixed at the leak prevention insertion portion suchthat the increase in the amount of exposure due to the heat expansion isprevented while keeping the hollow state of the tubular structure.

Instead of the seal member configured to expand by the pressuredifference as disclosed in PTL 1, a seal member configured to becompressed (crushed) in the cross sectional direction by a load may beused. However, according to the seal member configured to be compressed,as a seal length of the segment (the member or the tile in PTL 1)constituting the mold (the composite tool in PTL 1) increases, the loadfor compressing the seal member increases. The load may further increasedepending on the hardness and shape of the seal member.

Therefore, when one segment is moved to be combined with the othersegment, the segment needs to be moved by a large load for compressingthe seal member. In order to manufacture high-quality composite materialstructures, it is preferable that a level difference be little betweenouter peripheral surfaces of the adjacent segments. However, as the loadduring the movement of the segment increases, the degree of difficultyof position adjustment of the segments increases. Therefore, assemblywork of the mold becomes complex.

The present invention was made to solve the above problems, and anobject of the present invention is to, in a method of manufacturing acomposite material structure by using a mold constituted by a pluralityof segments, suppress or avoid complication of manufacturing steps whilerealizing a satisfactory sealed state between the adjacent segments ofthe mold.

Solution to Problem

To solve the above problems, a method of manufacturing a compositematerial structure according to the present invention is a method ofmanufacturing a hollow composite material structure including a skinconstituted by at least a thermosetting resin composition and a fibermaterial, the method using a mold located in the hollow compositematerial structure, the mold being constituted by a plurality ofsegments and kept as a single structure by coupling adjacent sidesurfaces of the segments to each other. The method includes: laminatinga prepreg on an outer peripheral surface of the mold, the prepreg beingconfigured to become the skin by thermal curing; forming a vacuum bagafter the prepreg is laminated, the vacuum bag being configured to sealan outside of the mold; and inserting seal members in seal grooves eachprovided on at least one of the adjacent side surfaces of the segments,each of the seal members being formed in a line shape having ends. Apart of the seal member which part contacts a bottom surface of the sealgroove when the seal member is inserted in the seal groove is referredto as a seal bottom portion. A part of the seal member which part isopposed to the seal bottom portion is referred to as a seal upperportion. A lip portion is provided at the seal upper portion such thatat least a tip end of the lip portion projects to an outside of the sealgroove when the seal member is inserted in the seal groove. The sealmember is hollow therein or includes a concave portion on at least theseal bottom portion of the seal member. When assembling the segments asthe single structure, the adjacent side surfaces of the segments arecoupled to each other, and the seal member provided at one of thesegments is crushed in a cross sectional direction by the side surfaceof the other segment to seal between the segments. The method furtherincludes, while subjecting an inside of the vacuum bag to vacuumsuction, subjecting the prepreg to the thermal curing while beingpressurized by autoclaving of the entire mold.

According to the above configuration, the seal structure including theseal member configured as above is provided between the adjacentsegments. The seal member includes the lip portion and the hollow orconcave portion and is formed in a line configuration having ends.Therefore, regarding the cross sectional direction of the seal member,the sealed state can be formed by compressing the seal member withoutapplying a high load. Regarding the longitudinal direction of the sealmember, the expansion (linear expansion) in the longitudinal directiongenerated by the heating during the autoclaving can be easily adjustedby both end portions of the seal member.

With this, the more satisfactory and stable sealed state can be realizedbetween the adjacent segments. Therefore, when the vacuum bag is formedon the outer peripheral surface of the mold, the inside of the vacuumbag can be satisfactorily subjected to vacuum suction. Therefore, duringthe autoclaving, the prepreg located outside the mold and inside thevacuum bag can be satisfactorily pressurized.

In addition, since the increase in the moving load of the segment can besuppressed or avoided, the level difference between the adjacentsegments can be satisfactorily adjusted when assembling the mold. Withthis, the accuracy of the outer peripheral surface of the mold improves,so that the high quality skin can be formed. As a result, thecomplication of the manufacturing steps can be suppressed or avoidedwhile realizing the satisfactory sealed state between the adjacentsegments of the mold.

Advantageous Effects of Invention

According to the above configuration, the present invention has aneffect of being able to, in a method of manufacturing a compositematerial structure by using a mold constituted by a plurality ofsegments, suppress or avoid complication of manufacturing steps whilerealizing a satisfactory sealed state between the adjacent segments ofthe mold.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic perspective view showing one example of theconfiguration of a mold used in a method of manufacturing a compositematerial structure according to the present embodiment. FIG. 1B is aschematic end surface view showing one example of the configuration of amandrel included in the mold shown in FIG. 1A.

FIG. 2A is a perspective view showing the configuration of a firstsegment forming a cylindrical structure of the mold shown in FIGS. 1Aand 1B. FIG. 2B is a surface view showing an end portion of the firstsegment shown in FIG. 2A.

FIG. 3A is a perspective view showing the configuration of a secondsegment forming the cylindrical structure of the mold shown in FIGS. 1Aand 1B. FIG. 3B is a surface view showing an end portion of the secondsegment shown in FIG. 3A.

FIG. 4 is a schematic perspective view showing one example of assemblingof the mold shown in FIG. 1A.

FIGS. 5A to 5D are schematic diagrams showing specific steps ofassembling the mold shown in FIG. 4.

FIGS. 6A to 6D are schematic diagrams showing specific steps ofassembling the mold shown in FIG. 4, the steps being performed after thesteps shown in FIGS. 5A to 5D.

FIG. 7 is a process diagram showing one example of the method ofmanufacturing the composite material structure according to the presentembodiment.

FIGS. 8A to 8C are partial sectional views each showing one end portionof the first segment of the mold for manufacturing the compositematerial structure shown in FIG. 1A and schematically show a part of aprocess of manufacturing the cylindrical composite material structure byusing the mold.

FIGS. 9A and 9B are partial sectional views each showing the mold formanufacturing the composite material structure shown in FIG. 1A and showone example of a seal structure according to the present invention, theseal structure being applied to the mold.

FIGS. 10A to 10F are cross sectional views showing typical examples of aseal member included in the seal structure shown in FIG. 9A or 9B.

FIG. 11A is a partial perspective view of the first segment and showsthat a seal end portion pressing member included in the seal structureshown in FIG. 9A or 9B is not attached yet.

FIG. 11B is a partial perspective view of the first segment and showsthat the seal end portion pressing member is attached to the firstsegment shown in FIG. 11A.

FIGS. 12A to 12D are schematic process diagrams showing a process ofconstructing the seal structure shown in FIG. 9B.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a representative embodiment of the present invention willbe explained with reference to the drawings. In the followingexplanations and the drawings, the same reference signs are used for thesame or corresponding components, and a repetition of the sameexplanation is avoided.

Mold for Manufacturing Composite Material Structure

First, a mold used in a method of manufacturing a composite materialstructure according to the present embodiment will be explained withreference to FIGS. 1A to 4.

As shown in FIG. 1A, a mold 10 according to the present embodimentincludes at least a mandrel 11 and a pair of support rings 12. Themandrel 11 is a single cylindrical structure (cylindrical member), andthe support rings 12 are located at both ends of the mandrel 11. Themandrel 11 is formed by coupling side surfaces of six segments, i.e.,three first segments 20 and three second segments 30 to one another. Asschematically shown in FIG. 1B, in the mandrel 11, the first segments 20and the second segments 30 are alternately coupled to one another. Bothends of the mandrel 11 are supported by the respective support rings 12.Thus, the six segments 20 and 30 are kept in a cylindrical shape.

As shown in FIG. 1A, a plurality of vacuum suction holes 13 are providedon surfaces of both end portions of the segments 20 and 30. Each of endportions of a seal groove 25 is exposed between a peripheral edgesurface of an end portion of the segment 20 and a peripheral edgesurface of an end portion of the adjacent segment 30. A below-describedseal member is inserted into the seal groove 25. In FIG. 1B, parts Pssurrounded by dotted lines are positions at which seal structures of themold 10 are provided. The parts Ps correspond to positions at each ofwhich the side surface of the first segment 20 and the side surface ofthe second segment 30 are coupled to each other. The seal structureaccording to the present embodiment includes the seal groove 25 shown inFIG. 1A. The seal structure will be described later.

Groove-shaped concave portions to which stringers are attached areformed on an outer peripheral surface of the mandrel 11 except forperipheral edges of both end portions of the mandrel 11. In order toclearly show the configurations of the mandrel 11 and the segments 20and 30, the groove-shaped concave portions are not shown in FIG. 1A andthe other drawings showing the mandrel 11 and the segments 20 and 30.

The sectional shape of the mandrel 11, i.e., the shape of an end surfaceof the mandrel 11 formed by the end surfaces of the first segments 20and the end surfaces of the second segments 30 is not especially limitedas long as it is an annular shape. In the present embodiment, when thecomposite material structure manufactured by using the mold 10 is, forexample, a one-piece barrel (OPB) constituting a fuselage of anaircraft, the shape of the end surface of the mandrel 11 is an oval, nota perfect circle. Needless to say, the sectional shape of the mandrel 11may be a perfect circle depending on the shape of the composite materialstructure to be manufactured.

When the shape of the end surface of the mandrel 11 (or the sectionalshape of the mandrel 11) is an oval shape, the shapes of the segments 20and 30 are slightly different from one another. To be specific, when thesectional shape of the mandrel 11 (the shape of the end surface of themandrel 11) is a perfect circle, the segment front surfaces 21 of thethree first segments 20 have the same curvature, and therefore, thethree first segments 20 are the same in shape as one another. Similarly,the three second segments 30 are the same in shape as one another.However, when the sectional shape of the mandrel 11 is an oval, in themandrel 11 shown in, for example, FIG. 1B, the first segment 20 locatedat an upper position and the second segment 30 located at a lowerposition are different in surface curvature from the first segments 20and the second segment 30 located at the other positions, and therefore,these segments are not the same in shape as one another.

As described above, the support rings 12 support both ends of themandrel 11. Each of the support rings 12 has an annular perfect circleshape. Opposing surfaces of the support rings 12 serve as fixingsurfaces for fixing the end surfaces of the mandrel 11. A fixing member(not shown) is provided on each fixing surface so as to correspond tothe segment 20 or 30 to be fixed. The shape of the support ring 12 doesnot have to be a perfect circle as long as the support ring 12 isrotatable. For example, the support ring 12 may have an oval shape.

As shown in FIG. 2A, the first segment 20 is formed in a rectangularflat plate shape. A surface of the first segment 20 which surfaceconstitutes the outer peripheral surface of the mandrel 11 is referredto as a “segment front surface 21,” and the segment front surface 21 isa convex curved surface (a convex surface or a projectingly curvedsurface). Further, the peripheral edge surfaces of both end portions ofthe first segment 20 are referred to as “segment end portion surfaces22,” and the vacuum suction holes 13 are provided on the segment endportion surfaces 22.

A surface of the first segment 20 which surface is coupled to theadjacent second segment 30 is referred to as a “segment side surface23.” As shown in FIGS. 2A and 2B, when the first segment 20 ishorizontally arranged with the segment front surface 21 facing upward,the seal grooves 25 are provided on the segment side surfaces 23 in alongitudinal direction of the segment side surface 23. In the presentembodiment, as shown in FIG. 2A, both end portions of the seal groove 25are bent toward the respective segment end portion surfaces 22.

A surface of the first segment 20 which surface constitutes an endsurface of the mandrel 11 is referred to as a “segment end surface 24.”As shown in FIGS. 2A and 2B, the seal groove 25 cannot be visuallyconfirmed from the segment end surface 24. Therefore, in FIG. 2B, theseal grooves 25 are shown by broken lines. In order to couple thesegment side surface 23 of the first segment 20 to the side surface ofthe second segment 30, a coupling member (not shown) is provided on thesegment side surface 23 of the first segment 20. In order to fix thesegment end surface 24 to the support ring 12, a fixing member (notshown) is provided on the segment end surface 24.

Each of both segment side surfaces 23 of the first segment 20 faces ahorizontal direction or a direction inclined upward relative to thehorizontal direction. In the present embodiment, as shown in FIG. 2B,for example, a normal direction of the segment side surface 23 extendsin the direction inclined upward relative to the horizontal direction.

As described below, in the present embodiment, when assembling themandrel 11 in a cylindrical shape, the second segments 30 are firstfixed to the support rings 12, and each of the first segments 20 is thenfitted between the second segments 30 from a lower side to an upper sideto be fixed. Therefore, in order not to hinder this fitting work, thesegment side surface 23 of the first segment 20 is only required to beformed such that the normal direction of the segment side surface 23extends (is directed) in the horizontal direction (direction shown by anarrow Ar1 in FIG. 2B). In other words, when the first segment 20 isarranged horizontally, the segment side surface 23 is located along avertical direction (direction along a one-dot chain line shown in FIG.2B).

After the cylindrical composite material structure (for example, theOPB) is molded by using the mold 10 including the mandrel 11, thecomposite material structure is removed from the mold 10. This removalis performed by disassembling the mandrel 11. The disassembling of themandrel 11 is performed in the reverse order to the assembling of themandrel 11. Therefore, each of the first segments 20 is pulled out frombetween the second segments 30.

On this account, as shown in FIG. 2B, it is preferable that the segmentside surface 23 of the first segment 20 be formed such that the normaldirection of the segment side surface 23 is inclined upward (toward thesegment front surface 21, i.e., in a direction shown by an arrow Ar2 inFIG. 2B). The upward inclination of the normal direction of the segmentside surface 23 denotes that the segment side surface 23 is inclined soas to face upward. In other words, the segment side surface 23 isinclined such that a rear-side edge of the segment side surface 23spreads more outward than a front-side edge of the segment side surface23. The inclination of the segment side surface 23 form “draft” on thesegment side surface 23 of the first segment 20. Thus, the first segment20 is easily pulled out from between the second segments 30, andtherefore, the mandrel 11 is easily disassembled.

The inclination angle (draft angle) of the segment side surface 23 isnot especially limited and is suitably set to a preferred angledepending on specific shapes, dimensions, and the like of the mandrel 11and the mold 10. For example, in the present embodiment, the inclinationangle (draft angle) of the segment side surface 23 may be set to 8 to 12degrees, preferably about 10 degrees. The inclination angles of theopposing segment side surfaces 23 may be equal to each other ordifferent from each other.

As shown in FIG. 3A, as with the first segment 20, the second segment 30is formed in a rectangular flat plate shape. A surface of the secondsegment 30 which surface constitutes the outer peripheral surface of themandrel 11 is referred to as a “segment front surface 31,” and thesegment front surface 31 is a convex curved surface as with the segmentfront surface 21 of the first segment 20. Further, as with the firstsegment 20, the peripheral edge surfaces of both end portions of thesecond segment 30 are referred to as “segment end portion surfaces 32,”and the vacuum suction holes 13 are provided on the segment end portionsurfaces 32.

A surface of the second segment 30 which surface is coupled to theadjacent first segment 20 is referred to as a “segment side surface 33.”Each of both segment side surfaces 33 has a shape that faces a directioninclined downward relative to the horizontal direction. To be specific,both segment side surfaces 33 are inclined such that the width of thesecond segment 30 increases from a rear side of the second segment 30toward the segment front surface 31.

As described below, in the present embodiment, when assembling themandrel 11 in a cylindrical shape, the second segments 30 are firstfixed to the support rings 12, and each of the first segments 20 is thenfitted between the second segments 30. Therefore, in order not to hinderthe fitting work of the first segment 20, it is preferable that the areaof the rear side of the second segment 30 fixed first be small. On thisaccount, it is preferable that each of both segment side surfaces 33 ofthe second segment 30 be formed such that the normal direction of thesegment side surface 33 extends downward (direction shown by an arrowAr3 in FIG. 3B), in other words, the segment side surface 33 is inclineddownward.

In order to couple the segment side surface 33 to the segment sidesurface 23 of the first segment 20, a coupling member (not shown) isprovided on the segment side surface 33. A surface of the second segment30 which surface constitutes the end surface of the mandrel 11 isreferred to as a “segment end surface 34.” In order to fix the segmentend surface 34 to the support ring 12, a fixing member (not shown) isprovided on the segment end surface 34 as with the segment end surface24 of the first segment 20.

An eave portion 35 projecting outward from the segment side surface 33is provided at an edge portion of the segment side surface 33 of thesecond segment 30, the edge portion being connected to the segment frontsurface 31. Therefore, as shown in FIGS. 3A and 3B, when the secondsegment 30 is viewed from the segment front surface 31, the segment sidesurfaces 33 facing downward are completely hidden by the eave portions35.

The degree of the downward inclination of the segment side surface 33and the degree of the projection of the eave portion 35 are notespecially limited and are suitably set in accordance with the specificconfiguration of the mandrel 11, the specific configuration of thesecond segment 30, or the specific configuration of the first segment 20coupled to the second segment 30.

As shown in FIG. 3B, an end surface of the eave portion 35 constitutes apart of the segment side surface 33. Therefore, the segment side surface33 of the second segment 30 is constituted by two surfaces that are amain body side surface of the second segment 30 and the end surface ofthe eave portion 35 projecting from the main body side surface. However,the specific configuration of the segment side surface 33 is notespecially limited, and the segment side surface 33 may be constitutedby a single surface without a level difference or may be constituted bythree or more surfaces.

In the present embodiment, the end surface of the eave portion 35 in thesegment side surface 33 is coupled to a part of the segment side surface23 of the first segment 20 (see the parts Ps in FIG. 1B). Thebelow-described seal structure is provided on the part of the segmentside surface 23 to which part the end surface of the eave portion 35 iscoupled. Therefore, the segment side surface 23 of the segment 20 andthe segment side surface 33 of the segment 30 do not have to be entirelyconnected to each other, and as in the present embodiment, a part of thesegment side surface 23 and a part of the segment side surface 33 may beconnected to each other.

A rear surface of the first segment 20 shown in FIG. 2B and a rearsurface of the second segment 30 shown in FIG. 3B are flat surfaces.However, the specific configurations of the first segment 20 and thesecond segment 30 are not limited to these. Each of the segments 20 and30 does not have to include the rear surface, and an internalconfiguration, such as a skeleton structure, for constituting thesegment 20 or 30 may be exposed. Since it is preferable that the outerperipheral surface of the mandrel 11 be as smooth as possible, thesegment front surface 21 and the segment front surface 31 constitutingthe outer peripheral surface of the mandrel 11 are only required to besmooth curved surfaces, and it is unnecessary to form a flat surface ata rear side when viewed from the segment front surface 21 or the segmentfront surface 31.

The segment front surfaces 21 of the first segments 20 and the segmentfront surfaces 31 of the second segments 30 form the outer peripheralsurface of the mandrel 11. Therefore, as described above, thegroove-shaped concave portions to which the stringers are attached areformed on the outer peripheral surface of the mandrel 11 except for thesegment end portion surface 22 and the segment end portion surface 32(peripheral edges of both end portions of the mandrel 11). Further, aframe portion, such as a door frame portion or a window frame portion,is formed on at least one of the segment front surface 21 and thesegment front surface 31 depending on the type of the composite materialstructure. It should be noted that the groove-shaped concave portionsand the frame portions are not shown in FIGS. 2A, 2B, 3A, and 3B forconvenience of explanation.

Assembling of Mold

Next, one example of a method of assembling a plurality of segments 20and 30 as the mandrel 11 of the mold 10 configured as above (method ofassembling the mold 10) will be specifically explained with reference toFIGS. 4 to 6D.

First, as described above, regarding the mold 10 (see FIG. 1A), the sixsegments 20 and 30 are fixed to the support rings 12 to be assembled asthe mandrel 11 that is a single cylindrical structure.

Before the six segments 20 and 30 are assembled as the mandrel 11, someof parts constituting the composite material structure are attached tothe six segments 20 and 30. For example, as described above, thegroove-shaped concave portions (not shown) are provided on the segmentfront surfaces 21 of the segments 20 and the segment front surfaces 31of the segments 30, and stiffeners, such as stringers, are attached tothe groove-shaped concave portions. After such parts are attached to thesegments 20 and 30, the segments 20 and 30 are assembled to constructthe mandrel 11.

As shown in FIG. 4, the support rings 12 are supported in a standingstate by respective cradles 41 (mandrel support structures) so as to berotatable. Each of the cradles 41 includes a plurality of supportrollers configured to rotate the support ring 12. A pair of supportrings 12 are supported by a pair of cradles 41.

As described below, the mandrel 11 is formed by assembling the sixsegments 20 and 30. When assembling the segments, the support rings 12are rotated by the cradles 41. With this, the segments 20 and 30 arefixed to the support rings 12 by the same movement that is a liftingmovement from a lower side to an upper side, not by different movementsamong the segments 20 and 30.

A precision rail 42 (mandrel assembling/disassembling apparatus) isprovided at a position between the support rings 12 and corresponding tothe hollow portions of the annular support rings 12. The precision rail42 is an assembling apparatus by which the six segments 20 and 30 arefixed and assembled to the support rings 12. As shown in FIG. 4, theprecision rail 42 includes a jack portion 43, a rail main body 44, andthe like. One first segment 20 or one second segment 30 is placed on anupper side of the jack portion 43, and the jack portion 43 lifts thefirst segment 20 or the second segment 30 in a direction of 12 o'clock,i.e., upward. The rail main body 44 supports the jack portion 43 and thelike and includes, for example, a drive mechanism configured to drivethe jack portion 43.

Next, a method of fixing the six segments 20 and 30 to the support rings12 one by one to assemble the mandrel 11 will be specifically explained.

In the present embodiment, the three first segments 20 and the threesecond segments 30 are alternately coupled to one another to form anannular shape with the segment front surfaces 21 and the segment frontsurfaces 31 facing outward. With this, the single cylindrical mandrel 11is configured. Therefore, for convenience of explanation, in FIGS. 5A to5D and 6A to 6D, the three first segments 20 are shown as a No. 1 firstsegment 20 a, a No. 2 first segment 20 b, and a No. 3 first segment 20c, and the three second segments 30 are shown as a No. 1 second segment30 a, a No. 2 second segment 30 b, and a No. 3 second segment 30 c.

First, as shown in FIG. 5A, the No. 1 second segment 30 a is placed atthe jack portion 43 located on the rail main body 44 and is lifted inthe direction of 12 o'clock (a vertically upper direction shown by anarrow Lf in FIG. 5A) by the operation of the jack portion 43 to reach anupper position of the support rings 12. Fixing members (not shown) areprovided on the segment end surfaces 34 (see FIGS. 3A and 3B) of thesecond segment 30 a and the fixing surfaces of the support rings 12.With this, as shown in FIG. 5B, the No. 1 second segment 30 a is fixedand supported between the support rings 12.

Next, as shown by an arrow Rt1 in FIG. 5B, the support rings 12 arerotated by about 120 degrees. With this, the No. 1 second segment 30 afixed at the upper position in FIG. 5B is moved to a lower left positionshown in FIG. 5C. In this state, the No. 2 second segment 30 b is placedat the jack portion 43 (see FIG. 5A) and is moved upward by theoperation of the jack portion 43. Fixing members (not shown) areprovided on the segment end surfaces 34 of the second segment 30 b (seeFIGS. 3A and 3B) and the fixing surfaces of the support rings 12. Withthis, as shown in FIG. 5C, the No. 2 second segment 30 b is fixed andsupported between the support rings 12.

Next, as shown by the arrow Rt1 in FIG. 5C, the support rings 12 arerotated by about 120 degrees. With this, the No. 2 second segment 30 bfixed at the upper position in FIG. 5C is moved to the lower leftposition shown in FIG. 5D, and the No. 1 second segment 30 a is moved toa lower right position. In this state, the No. 3 second segment 30 c isplaced at the jack portion 43 (see FIG. 5A) and is moved upward by theoperation of the jack portion 43. Fixing members (not shown) areprovided on the segment end surfaces 34 of the second segment 30 c (seeFIGS. 3A and 3B) and the fixing surfaces of the support rings 12. Withthis, as shown in FIG. 5D, the No. 3 second segment 30 c is fixed andsupported between the support rings 12.

After the No. 3 second segment 30 a is fixed to the support rings 12,the support rings 12 are rotated by about 60 degrees as shown by anarrow Rt2. When fixing the second segments 30 a to 30 c at first, thesecond segments 30 a to 30 c are fixed at every other fixing positionsof the support rings 12, so that the support rings 12 need to be rotatedby a rotation angle of 120 degrees corresponding to the fixing positionsof two segments. However, since the first segments 20 a to 20 cdifferent in type from the second segments 30 a to 30 c are fixed inthis step, the rotation angle is 60 degrees corresponding to onesegment.

With this, as shown in FIG. 6A, the No. 3 second segment 30 c fixed atthe upper position is moved to an upper left position, and the No. 2second segment 30 b and the No. 1 second segment 30 a are moved to thelower position and an upper right position, respectively. Therefore, inthis state, nothing is fixed at the upper position of the support rings12 in FIG. 6A.

As shown in FIG. 6A, the No. 1 first segment 20 a is placed at the jackportion 43 and lifted in the direction of 12 o'clock shown by an arrowLf to reach the upper position of the support rings 12. In this state,as shown in FIG. 6B, the No. 1 first segment 20 a is inserted betweenthe No. 3 second segment 30 c and the No. 1 second segment 30 a.

The seal groove 25 and the seal member 26 inserted in the seal groove 25are provided on each of both segment side surfaces 23 of the firstsegments 20 a to 20 c. To be specific, the seal structure configured toseal between the adjacent segments 20 and 30 is provided on each of thesegment side surfaces 23 of the first segments 20 a to 20 c. Asdescribed below, according to the seal structure, since the seal member26 can be crushed in the cross sectional direction without a high movingload, a sealed state can be easily realized between the adjacentsegments 20 and 30.

Fixing members (not shown) are provided on the segment end surfaces 24of the No. 1 first segment 20 a (see FIGS. 2A and 2B) and the fixingsurfaces of the support rings 12. With this, as shown in FIG. 6B, theNo. 1 first segment 20 a is fixed between the support rings 12. Further,coupling members (not shown) are provided on both segment side surfaces23 of the first segments 20 a to 20 c and both segment side surfaces 33of the second segments 30 a to 30 c. With this, the No. 3 second segment30 c and the No. 1 first segment 20 a are coupled to each other, and theNo. 1 second segment 30 a and the No. 1 first segment 20 a are coupledto each other.

Next, as shown by the arrow Rt1 in FIG. 6B, the support rings 12 arerotated by about 120 degrees. With this, the No. 1 first segment 20 afixed at the upper position in FIG. 6B is moved to the lower leftposition shown in FIG. 6C. In this state, the upper position of thesupport rings 12 in FIG. 6C corresponds to a position between the No. 1second segment 30 a and the No. 2 second segment 30 b, and nothing isfixed at this position. The No. 2 first segment 20 b is placed at thejack portion 43 (see FIG. 6A) and is moved upward in the direction of 12o'clock by the operation of the jack portion 43. With this, the firstsegment 20 b reaches the upper position of the support rings 12.

In this state, as shown in FIG. 6C, the No. 2 first segment 20 b isinserted between the No. 1 second segment 30 a and the No. 2 secondsegment 30 b. As described above, the sealed state between the segments20 and 30 is realized by the seal structure including the seal groove 25and the seal member 26. Further, as described above, by the fixingmembers (not shown) and the coupling members (not shown), the No. 2first segment 20 b is fixed between the support rings 12 and coupled tothe No. 1 second segment 30 a and the No. 2 second segment 30 b.

Next, as shown by the arrow Rt1 in FIG. 6C, the support rings 12 arerotated by about 120 degrees. With this, the No. 2 first segment 20 bfixed at the upper position in FIG. 6C is moved to the lower leftposition shown in FIG. 6D, and the No. 1 first segment 20 a is moved tothe lower right position. In this state, the upper position of thesupport rings 12 in FIG. 6D corresponds to a position between the No. 2second segment 30 b and the No. 3 second segment 30 c, and nothing isfixed at this position. The No. 3 first segment 20 c is placed at thejack portion 43 (see FIG. 6A) and is moved upward in the direction of 12o'clock by the operation of the jack portion 43. With this, the No. 3first segment 20 c reaches the upper position of the support rings 12.

In this state, as shown in FIG. 6D, the No. 3 first segment 20 c isinserted between the No. 2 second segment 30 b and the No. 3 secondsegment 30 c, and the sealed state between the segments 20 and 30 isrealized by the seal structure including the seal groove 25 and the sealmember 26. Further, as described above, by the fixing members (notshown) and the coupling member (not shown), the No. 3 first segment 20 cis fixed between the support rings 12 and coupled to the No. 2 secondsegment 30 b and the No. 3 second segment 30 c.

With this, all the first segments 20 a to 20 c are fixed to the supportrings 12, and all the segments 20 a to 20 c and 30 a to 30 c are coupledto and held one another. As a result, as shown in FIG. 1A, theassembling of the mold 10 constituted by the mandrel 11 held by thesupport rings 12 is completed.

Method of Manufacturing Composite Material Structure

Next, one example of a method of molding (manufacturing) the compositematerial structure by using the mold 10 assembled as above will bespecifically explained with reference to FIGS. 7 to 8C.

As described above, examples of the composite material structuremanufactured by the method of manufacturing the composite materialstructure according to the present embodiment include cylindricalstructures, such as the OPB, and typical examples are structuresconstituting aircrafts. Materials constituting the composite materialstructure are not especially limited and may be generally a matrixmaterial and a fiber material. The matrix material may be athermosetting resin or a thermosetting resin composition prepared byadding a material, an additive, or the like to a thermosetting resin.Further, the composite material structure may contain a material otherthan the thermosetting resin (or the thermosetting resin composition)and the fiber material.

Specific examples of the thermosetting resin include an epoxy resin, abismaleimide resin, a vinylester resin, an unsaturated polyester resin,a phenol resin, and a silicone resin. However, the thermosetting resinis not especially limited. Among these resins, only one type of resinmay be used, or plural types of resins suitably combined may be used.Typically, the epoxy resin is preferably used. The specific chemicalstructures of these thermosetting resins are not especially limited. Apolymer prepared by polymerizing various known monomers may be used, ora copolymer prepared by polymerizing plural monomers may be used.Further, structures, such as the average molecular weight, the mainchain, and the side chain, are not especially limited.

Specific examples of the fiber material includes a carbon fiber, anaramid fiber, a nylon fiber, a polyester fiber, and a glass fiber.However, the fiber material is not especially limited. Typically, thecarbon fiber having high strength and high rigidity is preferably used.Conditions, such as the shapes, lengths, and diameters of these fibermaterial, are not especially limited, and conditions suitable for thecomposite material structure can be selected. Among these fibermaterials, only one type of fiber material may be used, or two or moretypes of fiber materials suitably combined may be used. Further, thefiber materials may be constituted as braid, woven fabric, knit fabric,or the like.

In the method of manufacturing the composite material structureaccording to the present embodiment, the composite material structure ismolded on an outer peripheral surface of the mold 10 configured asabove. Specific steps of the method are not especially limited. In thepresent embodiment, one example of a manufacturing method including tensteps shown in FIG. 7 will be specifically explained.

First, the segments 20 and 30 (see FIGS. 2A, 2B, 3A, and 3B) aresubjected to a pretreatment before the segments 20 and 20 are assembled(pretreatment step P01). Details of the pretreatment are not especiallylimited. For example, the segment front surface 21 or the segment frontsurface 31 is washed and subjected to a release treatment in order tofacilitate the separation of the mold from the composite materialstructure after the molding.

Next, components of the composite material structure are attached to thesegment front surface 21 or the segment front surface 31 (componentattaching step P02). Examples of the components include: stringers andframes as skeleton members (stiffeners) of the composite materialstructure; and an innermost layer of the composite material structure.In the present embodiment, the stringers and the frames are made of acomposite material.

For example, as described above, the groove-shaped concave portions (notshown) to which the stringers are attached are formed on the segmentfront surfaces 21 and the segment front surfaces 31. The groove-shapedconcave portions are subjected to the washing treatment, the releasetreatment, and the like in the pretreatment step, and the stringers asthe components are attached to the groove-shaped concave portions. Thestringers are skeleton members provided along an axial direction of thehollow composite material structure and are attached to thegroove-shaped concave portions provided along the longitudinal directionof the segment front surface 21 or the segment front surface 31. Theframes are attached so as to be perpendicular to the stringers. Theframes are skeleton members provided along the circumferential directionof the composite material structure. The stringers and the frames arecoupled to each other by known coupling members, and the innermost layeris laminated on the outside of the stringers and the frames.

Next, the formation of the below-described seal structure on the segmentside surface 23 of the first segment 20 is prepared (seal structurepreparing step P03). Specifically, since the seal groove 25 is formed onthe segment side surface 23 (see FIGS. 2A and 2B), the below-describedseal member is inserted in the seal groove 25. The seal member is formedin a line shape having ends. The length of the seal member is set suchthat both end portions of the seal member are exposed from the sealgroove 25. As described below, the seal member inserted as above issubjected to an end portion treatment.

Next, as described above, the six segments 20 and 30 are assembled asthe mandrel 11 (see FIGS. 4 to 6D; mandrel assembling step P04). At thistime, each of the first segments 20 is inserted, from a lower side,between the second segments 30 fixed at every other fixing positions ofthe support rings 12. With this, the adjacent segment side surfaces 23and 33 of the segments 20 and 30 coupled to each other. The seal memberinserted in the seal groove 25 of the segment side surface 23 is crushedin the cross sectional direction by the segment side surface 33. Withthis, the below-described seal structure is formed and seals between theadjacent segments 20 and 30.

Next, the prepreg 50 is laminated on the outer peripheral surface of theassembled mandrel 11 (mold 10) as shown in FIG. 8A (prepreg laminatingstep P05). The prepreg 50 is an intermediate base material configured tobecome a skin by thermal curing. In the present embodiment, the prepreg50 is prepared by impregnating the fiber material, such as the carbonfiber, with the thermosetting resin (or the thermosetting resincomposition), such as the epoxy resin, and is in a semi-cured state (Bstage). The method of laminating the prepreg 50 is not especiallylimited. Typically, the prepreg 50 is laminated by being attached by anautomatic lamination apparatus including a lamination roller whilerotating the mandrel 11.

FIGS. 8A to 8C schematically show a part of a section of an end portionof the first segment 20 constituting the mandrel 11. Basically, thesecond segment 30 has the same configuration as FIGS. 8A to 8C.Therefore, the configuration of the first segment 20 explained withreference to FIGS. 8A to 8C corresponds to the configuration of thesecond segment 30 unless otherwise noted.

As schematically shown in FIGS. 8A to 8C, since the segment frontsurface 21 constitutes the outer peripheral surface of the mandrel 11,the prepreg 50 is laminated on the segment front surface 21. Asdescribed above, the segment end surface 24 of the first segment 20 isfixed by a fixing member 16. Further, as described above, the vacuumsuction holes 13 are provided on the segment end portion surface 22 ofthe first segment 20. As shown by broken lines in FIGS. 8A to 8C, avacuum suction pipe 14 is provided at the support ring 12.

After the lamination of the prepreg 50 is completed, a vacuum bag isformed on the outer peripheral surface of the mandrel 11 (mold 10)(vacuum bag forming step P06). The vacuum bag seals the outside of themold 10. For example, as shown in FIG. 8B, a bagging film 52 is providedso as to cover the entire prepreg 50, and a peripheral portion of thebagging film 52 is sealed by a bonding member 53 (for example, a tackeytape). Thus, the vacuum bag is formed. Therefore, the vacuum bag isconstituted by the outer peripheral surface of the mandrel 11 (mold 10)and the bagging film 52. At this time, the bagging film 52 covers notonly the segment front surface 21 (the outer peripheral surface of themandrel 11) on which the prepreg 50 is laminated but also a region ofthe segment end portion surface 22 at which region the vacuum suctionholes 13 are provided.

A caul plate 51 covering the prepreg 50 is attached to the outside ofthe prepreg 50. The caul plate 51 is a jig for forming a smooth surfaceat the outside of the composite material structure. Since the baggingfilm 52 covers the prepreg 50 from the outside of the caul plate 51, thecaul plate 51 is located inside the vacuum bag.

After the vacuum bag is formed, the mold 10 is accommodated in anautoclave. The prepreg 50 is subjected to a hardening treatment byapplying predetermined pressure to the entire mold 10 at a predeterminedtemperature while subjecting the inside of the vacuum bag to the vacuumsuction (autoclave step P07). Before the mold 10 is accommodated in theautoclave, as shown in FIG. 8C, one end of a connection hose 15 isconnected to the vacuum suction hole 13 from a rear surface of the firstsegment 20. The other end of the connection hose 15 is connected to thevacuum suction pipe 14 provided at the support ring 12. With this, asshown by a block arrow Vc in FIG. 8C, the inside of the vacuum bag canbe subjected to the vacuum suction through the vacuum suction hole 13.

When the hardening treatment is started in the autoclave, thepredetermined pressure is applied to the vacuum bag by the autoclavefrom the outside of the mandrel 11 as shown by a block arrow Pr in FIG.8C and is heated at the predetermined temperature. As described above,since the inside of the vacuum bag is subjected to the vacuum suction,the prepreg 50 is compressed while being heated.

The thermosetting resin in the semi-cured state (B stage) is oncesoftened by heating and is then heated continuously to be completelycured (C stage). Since the vacuum bag is constituted by the outerperipheral surface of the mandrel 11 and the bagging film 52 asdescribed above, the inner peripheral surface of the laminated prepreg50 contacts the outer peripheral surface of the mandrel 11, and theouter peripheral surface of the prepreg 50 contacts the caul plate 51.During the autoclaving, the prepreg 50 is heated while being pressurizedfrom the outside of the bagging film 52. Therefore, the thermosettingresin of the prepreg 50 is cured in a state where the pressure isapplied to the outer peripheral surface of the mandrel 11 by the caulplate 51.

Since the mandrel 11 is configured by coupling the segments 20 and 30,the outer peripheral surface of the mandrel 11 is configured such thatthe segment front surfaces 21 of the first segments 20 and the segmentfront surfaces 31 of the second segments 30 are continuous with oneanother. The below-described seal structure is formed between theadjacent first and second segments 20 and 30 by the seal structurepreparing step P03 and the mandrel assembling step P04, and therefore, asatisfactory sealed state is realized. On this account, the inside ofthe vacuum bag also becomes a satisfactory vacuum state, and thepressure of the autoclave is satisfactorily applied to the prepreg 50.

With this, the skeleton member (stiffener) provided on the outerperipheral surface of the mandrel 11 and the skin formed by curing theprepreg 50 strongly stick together to be integrated with each other.Thus, the composite material structure is molded. Therefore, the innerperipheral surface of the composite material structure is formed as anintegral smooth surface by the outer peripheral surface of the mandrel11, and the outer peripheral surface of the composite material structureis formed as an integral smooth surface by the caul plate 51.

After the hardening treatment is terminated, the mold 10 is carried outof the autoclave, and a debug treatment is performed (debug treatmentstep P08). For example, the bagging film 52 and the caul plate 51 aredetached in the debug treatment. After that, the composite materialstructure supported by the mandrel 11 is subjected to trimming andperforation (trimming step P09). Then, the mold 10 is removed from thecomposite material structure. Herein, the mold 10 is removed bydisassembling the mandrel 11 (mandrel disassembling step P10). Themethod of disassembling the mandrel 11 is performed in the reverse orderto the above-described method of assembling the mandrel 11. First, thefirst segments 20 a to 20 c are pulled out downward one by one to bedetached and removed from the inside of the composite materialstructure, and the second segments 30 a to 30 c are then moved downwardone by one to be detached from the inside of the composite materialstructure. Thus, the composite material structure is manufactured.

Seal Structure

Next, the seal structure provided between the first segment 20 and thesecond segment 30 constituting the mandrel 11 will be specificallyexplained with reference to FIGS. 9A to 10F.

The seal structure according to the present embodiment is providedbetween the adjacent segments 20 and 30. As shown in FIGS. 9A and 9B,the seal structure is constituted by at least the seal groove 25 and aseal member 26. As shown in FIGS. 10A to 10F, the seal member 26includes: a lip portion 262 or 265 projecting outward; and a hollowportion 263 therein or a concave portion 264 or 266 on an outerperipheral surface thereof.

The seal groove 25 is provided on at least one of the adjacent segmentside surfaces 23 and 33 of the segments 20 and 30 and extends along alongitudinal direction of the segment side surface 23 or 33. In thepresent embodiment, the seal groove 25 is provided on each of thesegment side surfaces 23 of the first segment 20 and is not provided onany of the segment side surfaces 33 of the second segment 30. Asdescribed above, the segment side surface 23 of the first segment 20faces the horizontal direction or the direction inclined upward relativeto the horizontal direction. Therefore, the seal structure is providedmore easily on the segment side surface 23 of the first segment 20 thanon the segment side surface 33 of the second segment 30.

FIGS. 9A and 9B schematically show only one end portion of the firstsegment 20 as a part of the mandrel 11. Although not shown, the otherend portion of the first segment 20 has the same configuration as FIG.9A or 9B. In FIGS. 9A and 9B, since the segment side surface 23 on whichthe seal groove 25 is provided is visible from a lateral side of thefirst segment 20, the segment side surface 23 is shown as a schematicpartial side view. However, in FIGS. 9A and 9B, in order to explain thelamination of the prepreg 50 on the segment front surface 21 and theformation of the vacuum bag, the vicinity of the segment front surface21 is shown as a schematic partial sectional view as with FIGS. 8B and8C.

The seal member 26 is inserted in the seal groove 25. The seal member 26seals between the adjacent segments 20 and 30 by coupling the sidesurfaces of the segments 20 and 30 to each other. When the adjacentsegments 20 and 30 are coupled to each other, a predetermined clearanceis kept between the segment side surface 23 and the segment side surface33. With the clearance kept, the seal member 26 is crushed by beingbrought into contact with the segment side surface 23 or the segmentside surface 33. Thus, the sealed state between the segments 20 and 30is realized.

The seal member 26 used in the present embodiment is not formed in anannular shape but is formed in a line shape having ends. The seal member26 having such line shape can be easily produced by, for example,extrusion molding at low cost. Since the seal member 26 is disposable,i.e., is basically used once in the autoclave and thrown away, theincrease in the manufacturing cost of the composite material structurecan be avoided by avoiding the increase in the manufacturing cost of theseal member 26.

As shown in FIG. 9A, at least one seal groove 25 is only required to beformed on the segment side surface 23. However, as shown in FIG. 9B, twoseal grooves 25 that are an outer seal groove 25 a and an inner sealgroove 25 b may be formed on the segment side surface 23. Although notshown, three or more seal grooves 25 may be formed on the segment sidesurface 23. Further, when a plurality of seal grooves 25 are formed, theseal members 26 of the same type may be inserted in the seal grooves 25,or the seal members 26 of different types may be inserted in the sealgrooves 25. For example, according to the configuration shown in FIG.9B, a first seal member 26 a is inserted into the outer seal groove 25a, and a second seal member 26 b different from the first seal member 26a is inserted into the inner seal groove 25 b. It should be noted thatthe configuration of an end portion of the seal member 26 will bedescribed later.

As described above, the seal member 26 includes: the lip portion 262 or265; and at least one of the hollow portion 263 and the concave portions264 and 266. The specific configurations of the lip portions 262 and265, the hollow portion 263, and the concave portions 264 and 266 arenot especially limited. However, the seal members 26A to 26F in FIGS.10A to 10F are shown as typical examples.

As shown in FIG. 10A, the seal member 26A includes: the hollow portion263 in a seal main body 261 thereof; and an upright lip portion 262 onan outer peripheral surface thereof. A part of the seal main body 261 ofthe seal member 26A which part contacts a bottom surface of the sealgroove 25 when the seal member 26A is inserted in the seal groove 25 isreferred to as a seal bottom portion, and a part of the seal main body261 of the seal member 26A which part is opposed to the seal bottomportion is referred to as a seal upper portion. The upright lip portion262 is provided so as to project from the substantially flat seal upperportion in a substantially normal direction of the seal upper portion.With the seal member 26A inserted in the seal groove 25, at least a tipend of the upright lip portion 262 projects to the outside of the sealgroove 25. A cross section of the seal main body 261 of the seal member26A has a rectangular shape, and the seal bottom portion is asubstantially flat surface.

As shown in FIG. 10B, the seal member 26B includes the upright lipportion 262 as with the seal member 26A. The seal member 26B does notinclude the hollow portion 263 but includes a bottom surface concaveportion 264 at the seal bottom portion thereof. The cross section of theseal main body 261 of the seal member 26B has a substantiallytrapezoidal shape, and the width of the seal upper portion is smallerthan the width of the seal bottom portion.

As above, according to the seal members 26A and 26B, the upright lipportion 262 is included at the seal upper portion, and the hollowportion 263 is included in the seal main body 261, or the bottom surfaceconcave portion 264 is included at the seal bottom portion. Each of thehollow portion 263 and the bottom surface concave portion 264 serves asa thinned part in the seal main body 261. Therefore, when the adjacentsegment side surfaces 23 and 33 of the segments 20 and 30 are coupled toeach other, each of the hollow portion 263 and the bottom surfaceconcave portion 264 is easily crushed by being pressed by the segmentside surface 33 of the second segment 30.

The upright lip portion 262 projects outward (in a direction toward thesecond segment 30) from the segment side surface 23 of the first segment20 and has elasticity derived from the material of the seal member 26Aor 26B. Therefore, the upright lip portion 262 tries to stand in a stateof contacting the segment side surface 33. With this, the inside of theseal groove 25 is satisfactorily sealed by the seal main body 261 andthe upright lip portion 262.

At this time, when viewing the seal members 26A and 26B from above, thehollow portion 263 or the bottom surface concave portion 264 is locatedsubstantially immediately under the upright lip portion 262, so that thehollow portion 263 or the bottom surface concave portion 264 which iseasily crushed and the upright lip portion 262 which is biased in thestanding direction by the elasticity are located on the substantiallysame straight line. Therefore, when assembling the mandrel 11, the sealmembers 26A and 26B can be compressed without applying a high load, anda satisfactory sealed state can be realized between the adjacentsegments 20 and 30. As a result, the segments 20 and 30 can be moved bya low load while securing the satisfactory sealed state, and therefore,the positions of the outer peripheral surfaces of the adjacent segments20 and 30 can be easily adjusted.

According to the seal member 26A shown in FIG. 10A and the seal member26B shown in FIG. 10B, the upright lip portion 262 in a substantiallyupright state is included, and the hollow portion 263 or the bottomsurface concave portion 264 as a deformation structure by which the sealmain body 261 is crushed in a cross sectional direction is located alongthe upright lip portion 262 on the substantially same straight line asthe upright lip portion 262. However, the seal member 26 according tothe present embodiment is not limited to this configuration. Forexample, as shown in FIGS. 10C to 10F, an inclined lip portion 265 maybe included instead of the upright lip portion 262.

For example, as shown in FIG. 10C, the seal member 26C includes theinclined lip portion 265 at the seal upper portion thereof. The inclinedlip portion 265 projects so as to be inclined relative to the normaldirection of the seal upper portion. A direction connecting the sealbottom portion and the seal upper portion in the cross section of theseal main body 261 is referred to as a “vertical direction of the crosssection of the seal member 26,” and a direction perpendicular to thevertical direction is referred to as a “lateral direction of the crosssection of the seal member 26.” Unlike the seal members 26A and 26B, thecross section of the seal main body 261 of the seal member 26C has a“laterally long” shape, not a “vertically long” shape that extends overthe entire cross section of the seal groove 25.

Therefore, in the seal member 26C, a movable space in which the inclinedlip portion 265 is movable in an upper-lower direction is formed betweenthe inclined lip portion 265 and the seal main body 261. As with theseal member 26B, the bottom surface concave portion 264 is formed at theseal bottom portion of the seal member 26C. In addition, the movablespace can also be regarded as a concave portion provided on the outerperipheral surface of the seal member 26C.

As shown in FIG. 10D, as with the seal member 26C, the seal member 26Dincludes the inclined lip portion 265, and the cross section of the sealmain body 261 has a “laterally long” shape. However, the seal member 26Dincludes the hollow portion 263 instead of the bottom surface concaveportion 264.

As above, according to the seal members 26C and 26D, the inclined lipportion 265 is included at the seal upper portion, and the bottomsurface concave portion 264 is included at the seal bottom portion ofthe seal main body 261 having a “laterally long” cross section, or thehollow portion 263 is included in the seal main body 261. When theadjacent segment side surfaces 23 and 33 of the segments 20 and 30 arecoupled to each other, the inclined lip portion 265 is easily presseddownward by the existence of the movable space immediately under theinclined lip portion 265, but the inclined lip portion 265 tries tostand by its elasticity in a state of contacting the segment sidesurface 33. Further, according to the seal main body 261 that is“laterally long,” the bottom surface concave portion 264 or the hollowportion 263 is crushed in accordance with the pressing of the inclinedlip portion 265. With this, the inside of the seal groove 25 issatisfactorily sealed by the seal main body 261 and the inclined lipportion 265.

Further, the seal member 26 according to the present embodiment mayinclude the inclined lip portion 265, and the width of the seal upperportion may be larger than the width of the seal bottom portion.

For example, as shown in FIG. 10E, the seal member 26E includes theinclined lip portion 265, and the bottom surface concave portion 264 isformed at the seal bottom portion. In addition, the width of the sealupper portion is larger than the width of the seal bottom portion, andan upper surface concave portion 266 is formed at a position of the sealupper portion which position is adjacent to the inclined lip portion265.

Further, as shown in FIG. 10F, the seal member 26F includes the inclinedlip portion 265, and the bottom surface concave portion 264 is formed atthe seal bottom portion. In addition, the width of the seal upperportion is larger than the width of the seal bottom portion, and thehollow portion 263 is formed in the seal main body 261.

As above, according to the seal members 26E and 26F, the inclined lipportion 265 is included at the seal upper portion larger in width thanthe seal bottom portion, and the bottom surface concave portion 264 isincluded at the seal bottom portion, or the hollow portion 263 isincluded in the seal main body 261. When the adjacent segment sidesurfaces 23 and 33 of the segments 20 and 30 are coupled to each other,the inclined lip portion 265 is easily pressed downward by the existenceof the movable space immediately under the inclined lip portion 265, butthe inclined lip portion 265 tries to stand by its elasticity in a stateof contacting the segment side surface 33. Further, according to theseal main body 261, the bottom surface concave portion 264 or the hollowportion 263 is crushed in accordance with the pressing of the inclinedlip portion 265. In addition, since the seal upper portion is wide, theseal groove 25 can be satisfactorily sealed in a width directionthereof.

Especially, when the upper surface concave portion 266 is formed inaddition to the movable space as in the seal member 26E, or when thehollow portion 263 is formed in addition to the movable space as in theseal member 26F, an edge portion of the wide seal upper portion easilymoves toward an inner side of the seal main body 261 by the deformationof the upper surface concave portion 266 or the hollow portion 263.Therefore, the sealed state in the lateral direction of the crosssection can be improved by the wide seal upper portion. With this, theinside of the seal groove 25 is satisfactorily sealed by the seal mainbody 261, the inclined lip portion 265, and the wide seal upper portion.

The selection from the seal members 26A to 26F shown in FIGS. 10A to 10Fis not especially limited. The seal member 26 having a preferredcross-sectional shape can be selected depending on various conditions,such as the degree of the seal performance required for the sealstructure, the material of the seal member 26, and moving loads of thesegments 20 and 30. Further, as described below, when a plurality ofseal grooves 25 are formed on the segment side surface 23, the sealmembers 26 having different cross sections can be selected depending onconditions required for the respective seal grooves 25.

For example, according to the configuration shown in FIG. 9B, one of theseal members 26C to 26F each including the inclined lip portion 265 canbe used as the first seal member 26 a inserted in the outer seal groove25 a, and the seal member 26A or 26B including the upright lip portion262 can be used as the second seal member 26 b inserted in the innerseal groove 25 b.

High pressure is applied from the outside of the seal groove 25 by theautoclave. Therefore, any one of the seal members 26C to 26F is arrangedin the outer seal groove 25 a such that the pressure is applied to themovable region located immediately under the inclined lip portion 265.With this, the inclined lip portion 265 can be strongly biased towardthe standing side by not only the elasticity derived from the materialbut also the pressure difference. Thus, the further satisfactory sealedstate can be realized.

The inside of the seal groove 25 faces the inside of the vacuum bag. Inthe thermal curing by the autoclave, the matrix resin (thermosettingresin) constituting the prepreg 50 is once softened before being cured.At this time, there is a possibility that the softened matrix resinflows toward the seal groove 25. Therefore, it is preferable that theleak of the matrix resin be effectively prevented or suppressed.

To be specific, the second seal member 26 b inserted in the inner sealgroove 25 b is required to have performance (pressure seal performance)of redundantly sealing high pressure outside the vacuum bag, togetherwith the first seal member 26 a inserted in the outer seal groove 25 a.In addition, the second seal member 26 b inserted in the inner sealgroove 25 b is required to have performance (matrix resin sealperformance) of preventing the leak of the softened matrix resin in thevacuum bag. Therefore, the seal member 26A or 26B including the uprightlip portion 262 is arranged in the inner seal groove 25 b.

According to the seal member 26, the high pressure outside the vacuumbag can be satisfactorily sealed (the satisfactory pressure sealperformance can be realized) by the crushed upright lip portion 262. Inaddition, since the movable region and the upper surface concave portion266 are not provided around the upright lip portion 262, the upright lipportion 262 does not incline unlike the inclined lip portion 265.Therefore, the softened matrix resin generated in the vacuum bag can besatisfactorily stopped (the satisfactory matrix resin seal performancecan be realized) by the upright lip portion 262. In addition, since theupper surface concave portion 266 and the like are not included asdescribed above, the matrix resin can be prevented from staying in aconcave portion at an outer periphery of the seal member 26.

Configuration of End Portion of Seal Member

Next, a preferred configuration of the end portion of the seal member 26in the seal structure configured as above will be specifically explainedwith reference to FIGS. 9A, 9B, and 11A to 12D.

In the seal structure according to the present embodiment, the sealmember 26 inserted in the seal groove 25 is formed in a line shapehaving ends, not an annular shape. As described above, regarding thecross sectional direction of the seal member 26, by the lip portions 262and 265, the hollow portion 263, and the concave portions 264 and 266(see FIGS. 10A to 10F), the sealed state can be formed by compressingthe seal member 26 without applying a high load. On the other hand,regarding the longitudinal direction of the seal member 26, theexpansion (linear expansion) generated in the longitudinal direction bythe heating during the autoclaving can be easily adjusted by both endportions of the seal member 26.

Specifically, for example, as shown in FIGS. 9A and 9B, the linearexpansion of the seal member 26 can be adjusted only by pressing a sealend portion pressing member 27 against the end portion of the sealmember 26 such that the end portion is not exposed. The seal groove 25may have a line shape including an end portion that reaches the segmentend surface 24. However, as shown in FIGS. 9A and 9B, it is preferablethat the end portion of the seal groove 25 be bent toward the segmentend portion surface 22. With this, an opening of the end portion of theseal groove 25 is exposed on the segment end portion surface 22 of thefirst segment 20, and therefore, the seal end portion pressing member 27can be provided on the segment end portion surface 22.

The segment end surface 24 of the first segment 20 is fixed to thesupport ring 12 through the fixing member 16. Therefore, if the seal endportion pressing member 27 is provided on the segment end surface 24,this may influence the movement of the first segment 20 during theassembling of the mandrel 11 and the fixing of the first segment 20 tothe support ring 12. However, since the seal end portion pressing member27 is provided on the segment end portion surface 22, such influences onthe assembling of the mandrel 11 can be avoided.

Further, as shown in FIGS. 9A and 9B, an edge portion of the baggingfilm 52 constituting the vacuum bag reaches the segment end portionsurface 22. When the end portion of the seal member 26 reaches thesegment end portion surface 22, the bagging film 52 also covers an upperside of the end portion of the seal member 26, and the seal end portionpressing member 27 can press the end portion of the seal member 26 fromabove.

The specific configuration of the seal end portion pressing member 27 isnot especially limited. As shown in FIGS. 9A, 9B, and 11B, the seal endportion pressing member 27 is only required to be a plate-shaped memberhaving rigidity and be fixed to the segment end portion surface 22 ofthe first segment 20 by a known fastening member 28 (for example, abolt). When the seal end portion pressing member 27 has rigidity, theseal end portion pressing member 27 can be pressed against the endportion of the seal member 26 by fixing only one of both end portions ofthe seal end portion pressing member 27 with the fastening member 28such that the end portion of the seal member 26 is not exposed. Withthis, as shown in FIGS. 9A, 9B, and 11A, a fastening member insertionhole 29 (shown only in FIG. 11A) can be provided at a position closer tothe segment end surface 24 than the seal groove 25. Therefore, forexample, an opening portion for the fastening member 28 does not have tobe formed on the bagging film 52, and therefore, the degree of vacuum ofthe vacuum bag can be prevented from deteriorating.

As described above, the cross section of the seal member 26 includes thelip portion 262 or 265, the hollow portion 263, the concave portion 264or 266, and the like (see FIGS. 10A to 10F). Therefore, even when theseal member 26 is inserted in the seal groove 25, a gap is necessarilyformed between the opening of the end portion of the seal groove 25exposed on the segment end portion surface 22 and the end portion of theseal member 26. On this account, as shown in FIGS. 9A and 9B, theopening of the end portion of the seal groove 25 and the end portion ofthe seal member 26 are only required to be covered with a bonding member54 (for example, a tackey tape) and then pressed by the seal end portionpressing member 27.

Especially when a plurality of seal grooves 25 are provided, and aplurality of seal members 26 are used, the end portions of the sealmembers 26 are covered with the bonding member 54, and with this, theend portions of the seal members 26 are connected to one another, andtherefore, the seal members 26 can be formed as a single seal member.Thus, the more satisfactory and stable sealed state can be realizedbetween the adjacent segments 20 and 30.

As described above, the bonding member 53 seals the entire peripheralportion of the bagging film 52. The bonding member 53 needs to beconnected to the bonding member 54 covering the end portion of the sealmember 26. With this, the vacuum bag sealed by the bonding members 53and 54 and the seal member 26 is formed. In the schematic sections shownin FIGS. 9A and 9B, only the bonding member 54 is shown. However, inorder to indicate that the bonding member 53 is connected to the bondingmember 54, the reference sign 53 with parentheses is also shown.

Next, one example of the adjustment of the end portions of the sealmembers 26 by the seal end portion pressing member 27 will be explainedby using an example in which as shown in FIGS. 9B, 11A, and 11B, theouter seal groove 25 a and the inner seal groove 25 b are provided asthe seal grooves 25, and the first seal member 26 a and the second sealmember 26 b are used as the seal members 26.

First, as schematically shown in FIG. 12A, the first seal member 26 a isinserted in the outer seal groove 25 a formed on the segment sidesurface 23 of the first segment 20, and the second seal member 26 b isinserted in the inner seal groove 25 b formed on the segment sidesurface 23 of the first segment 20. Both end portions of the first sealmember 26 a and both end portions of the second seal member 26 b areexposed from the openings of the end portions of the outer seal groove25 a and the openings of the end portions of the inner seal groove 25 bon the segment end portion surface 22. It should be noted that theprepreg 50 is laminated on the segment front surface 21, and the caulplate 51 is placed on the prepreg 50.

Next, as shown in FIG. 12B, each of both end portions of the first sealmember 26 a exposed from the openings of the end portions of the outerseal groove 25 a and both end portions of the second seal member 26 bexposed from the openings of the end portions of the inner seal groove25 b is cut so as to have a length of about several millimeters from thesegment end portion surface 22. Then, as shown in FIG. 12C, each of thebonding members 54 cover the opening of the end portion of the outerseal groove 25 a and the opening of the end portion of the inner sealgroove 25 b so as to connect the end portion of the first seal member 26a and the end portion of the second seal member 26 b to each other. Withthis, the above-described end portion treatment with respect to the sealmember 26 is completed.

By this end portion treatment, the first seal member 26 a and the secondseal member 26 b can be regarded as a single seal member. The singleseal member has an annular structure in appearance. In the presentembodiment, two seal grooves 25 (the outer seal groove 25 a and theinner seal groove 25 b) are provided on the segment side surface 23, andtwo seal members 26 (the first seal member 26 a and the second sealmember 26 b) are inserted in the seal grooves 25. When the number ofseal grooves 25 is one, and the number of seal members 26 is one, theend portion treatment is completed by cutting the end portion of theseal member 26 and covering the end portion with the bonding member 54.Therefore, in the end portion treatment with respect to the seal member26, the formation of the annular structure by the bonding members 54 isnot essential.

After that, as shown in FIG. 12D, the bagging film 52 covers the segmentfront surface 21 of the first segment 20 (i.e., covers the prepreg 50formed on the outer peripheral surface of the mandrel 11 and the caulplate 51 placed on the prepreg 50), and the seal end portion pressingmembers 27 are attached onto the bagging film 52. With this, the sealend portion pressing member 27 presses, from above the bagging film 52,the bonding member 54 by which the end portion of the first seal member26 a and the end portion of the second seal member 26 b are connected toeach other. Therefore, the end portions of the first seal member 26 aand the second seal member 26 b can be effectively prevented from beingexposed from the segment end portion surface 22 even during theautoclaving.

The bonding member 53 for bonding the peripheral portion of the baggingfilm 52 and the fastening member 28 (see FIG. 9B) for fixing the sealend portion pressing member 27 are not shown in FIG. 12D for convenienceof explanation. The bonding member 54 covering the openings of the endportions of the seal grooves 25 is not limited to the configurationsshown in FIGS. 12C and 12D. Without connecting the end portion of thefirst seal member 26 a and the end portion of the second seal member 26b as schematically shown in FIG. 9B, only the opening of the end portionof the outer seal groove 25 a may be covered with one bonding member 54,and only the opening of the end portion of the inner seal groove 25 bmay be covered with another bonding member 54.

Modified Example

The present embodiment describes the method of manufacturing thecomposite material structure, the method including a plurality of stepsshown in FIG. 7, for example. However, the manufacturing methodaccording to the present disclosure is not limited to this. Themanufacturing method may be such that: the vacuum bag is formed bylaminating the prepreg 50 on the outer peripheral surface of the mold 10including the above-described seal structure; the entire mold 10 issubjected to autoclaving while subjecting the inside of the vacuum bagto the vacuum suction; and with this, the prepreg 50 is thermally curedwhile being pressurized. Therefore, in the manufacturing methodaccording to the present disclosure, some of the steps P01 to P10 shownin FIG. 7 may be omitted, or a step(s) not shown in FIG. 7 may be added.

The mold used in the method of manufacturing the composite materialstructure according to the present disclosure is not limited to the mold10 (see FIGS. 1A to 4) including the mandrel 11 constituted by the sixsegments 20 and 30 as described in the present embodiment. The moldaccording to the present disclosure is only required to be locatedinside a hollow composite material structure, be constituted by aplurality of segments, and be kept as a single structure by couplingadjacent side surfaces of the segments to each other.

The specific shape of the mold is not limited to the above-describedcylindrical shape (a hollow shape with a substantially constant overalldiameter) and may be a conical tubular shape (a hollow shape thatdecreases in diameter from one end to the other) or a truncated conetubular shape (a hollow shape in which diameters of both ends aredifferent from each other, and an intermediate diameter graduallychanges). The seal structure according to the present disclosure is onlyrequired to be provided at the adjacent side surfaces of the segmentsconstituting the mold configured as above. Further, the shape of eachsegment is not limited to the rectangular flat plate shape, and variousshapes may be adopted as long as the segments can constitute the mandrel11 as a single structure.

Further, in the present embodiment, the mandrel 11 is constituted by thethree first segments 20 and the three second segments 30 (see FIG. 1B).However, the configuration of the mandrel 11 is not limited to this. Forexample, the number of segments may be five or less or may be seven ormore. The types of the segments are not limited to two types that arethe first segment 20 and the second segment 30. A segment different intype from the segments 20 and 30 may be included, or two or more typesof segments different in type from the segments 20 and 30 may be used.Or, the mandrel 11 may be constituted by segments of only one type.

As above, according to the mold of the present embodiment, the number ofdivided parts of the mold and the shapes of the individual segments arenot especially limited as long as the mandrel constituted by pluraltypes of segments is fixed to annular holding members, such as thesupport rings 12, to be kept in a hollow shape. To be specific,according to the mold of the present embodiment, the specific shapes ofthe segments, the types of the segments, the number of segments, and thelike are not especially limited as long as the mandrel (singlestructure) is assembled by connecting a plurality of segments eachhaving a substantially rectangular shape and divided along linesextending in an axial direction of the mandrel. The annular holdingmembers holding the plurality of segments constituting the mandrel arenot limited to the support rings 12, and different members may be used.For example, end rings may be used instead of the support rings 12.

In the present embodiment, the seal groove is provided at the firstsegment 20 including the segment side surfaces 23 facing the horizontaldirection or the direction inclined upward relative to the horizontaldirection. However, the configuration of the seal groove is not limitedto this. The seal groove may be provided on the segment side surface 33of the second segment 30, or the segment grooves may be provided on boththe segment side surface 23 and the segment side surface 33. To bespecific, in the present embodiment, some of the segments have the sealgrooves on the side surfaces, and the other segments do not have theseal grooves. However, all the segments may have the seal grooves.

In the present embodiment, the seal grooves are provided only at thefirst segments 20. However, the configuration of the seal grooves is notlimited to this. To be specific, the seal groove may be provided on onlyone of the adjacent side surfaces of the segments, or the sealstructures may be provided on both of the adjacent side surfaces of thesegments. Examples of a case where the seal grooves are provided at allthe segments include a configuration in which the seal groove isprovided on only one of both side surfaces of each segment and aconfiguration in which the seal grooves are provided on both sidesurfaces of each segment. When the seal groove is provided on only oneof both side surfaces of each segment, this corresponds to theconfiguration in which the seal groove is provided on only one of theadjacent side surfaces of the segments. When the seal grooves areprovided on both side surfaces of each segment, this corresponds to theconfiguration in which the seal grooves are provided on both of theadjacent side surfaces of the segments.

When the seal grooves are provided at both of the adjacent segments, itis preferable that the seal grooves be displaced from each other. Oneexample may be a configuration in which: the outer seal groove and thefirst seal member are provided on one of the adjacent side surfaces ofthe segments; and the inner seal groove and the second seal member areprovided on the other side surface. Further, in the present embodiment,the number of seal grooves formed on the side surface of the segment isone (see FIG. 9A) or two (see FIG. 9B), and the number of seal memberseach inserted in the seal groove is one or two. However, the number ofseal grooves and the number of seal members are not limited to these.The number of seal grooves may be three or more, and the number of sealmembers may be three or more. It should be noted that when a pluralityof seal grooves are provided on the side surface of the segment, acomponent (for example, a vacuum suction hole) for performing the vacuumsuction between the seal grooves may be additionally provided.

The specific configuration of the seal member inserted in the sealgroove is not especially limited. As described above, the seal member isonly required to: include the lip portion; and be hollow therein orinclude the concave portion on the outer peripheral surface thereof. Thespecific shape of the lip portion is not especially limited. The lipportion may be the upright lip portion 262, the inclined lip portion265, or a lip portion having a different shape and is only required tohave such a shape as to extend at the seal upper portion along thelongitudinal direction of the seal main body 261.

The concave portion is only required to be formed on at least the sealbottom portion. However, as described above, the concave portion may beformed on the seal upper portion so as to be located near the lipportion, or although not shown, the concave portion may be formed on theside surface of the seal main body. Basically, the hollow portion formedin the seal main body is only required to have a substantially circularsection. However, the hollow portion may have an oval section or apolygonal section. As with the lip portion, each of the hollow portionand the concave portion is only required to have such a shape as toextend along the longitudinal direction of the seal main body 261 in theseal main body or on the outer peripheral surface of the seal main body.

The width of the cross section of the seal member is not especiallylimited. The seal upper portion and the seal bottom portion may besubstantially the same in width as each other (see FIGS. 10A, 10C, and10D). The seal upper portion may be smaller in width than the sealbottom portion (see FIG. 10B). The seal upper portion may be larger inwidth than the seal bottom portion (see FIGS. 10E and 10F). A wideportion may be formed between the seal upper portion and the seal bottomportion (the side surface of the seal main body). The width of the sealmember may be reduced by the formation of the above-described concaveportion. A protruding portion may be formed on the side surface of theseal main body.

As above, a method of manufacturing a composite material structureaccording to the present disclosure is a method of manufacturing ahollow composite material structure including a skin constituted by atleast a thermosetting resin composition and a fiber material, the methodusing a mold located in the hollow composite material structure, themold being constituted by a plurality of segments and kept as a singlestructure by coupling adjacent side surfaces of the segments to eachother. The method includes: laminating a prepreg on an outer peripheralsurface of the mold, the prepreg being configured to become the skin bythermal curing; forming a vacuum bag after the prepreg is laminated, thevacuum bag being configured to seal an outside of the mold; andinserting seal members in seal grooves each provided on at least one ofthe adjacent side surfaces of the segments, each of the seal membersbeing formed in a line shape having ends. A part of the seal memberwhich part contacts a bottom surface of the seal groove when the sealmember is inserted in the seal groove is referred to as a seal bottomportion. A part of the seal member which part is opposed to the sealbottom portion is referred to as a seal upper portion. A lip portion isprovided at the seal upper portion such that at least a tip end of thelip portion projects to an outside of the seal groove when the sealmember is inserted in the seal groove. The seal member is hollow thereinor includes a concave portion on at least the seal bottom portion of theseal member. When assembling the segments as the single structure, theadjacent side surfaces of the segments are coupled to each other, andthe seal member provided at one of the segments is crushed in a crosssectional direction by the side surface of the other segment to sealbetween the segments. The method further includes, while subjecting aninside of the vacuum bag to vacuum suction, subjecting the prepreg tothe thermal curing while being pressurized by autoclaving of the entiremold.

According to the above configuration, the seal structure including theseal member configured as above is provided between the adjacentsegments. The seal member includes the lip portion and the hollow orconcave portion and is formed in a line configuration having ends.Therefore, regarding the cross sectional direction of the seal member,the sealed state can be formed by compressing the seal member withoutapplying a high load. Regarding the longitudinal direction of the sealmember, the expansion (linear expansion) in the longitudinal directiongenerated by the heating during the autoclaving can be easily adjustedby both end portions of the seal member.

With this, the more satisfactory and stable sealed state can be realizedbetween the adjacent segments. Therefore, when the vacuum bag is formedon the outer peripheral surface of the mold, the inside of the vacuumbag can be satisfactorily subjected to the vacuum suction. Therefore,during the autoclaving, the prepreg located outside the mold and insidethe vacuum bag can be satisfactorily pressurized.

In addition, since the increase in the moving load of the segment can besuppressed or avoided, the level difference between the adjacentsegments can be satisfactorily adjusted when assembling the mold. Withthis, the accuracy of the outer peripheral surface of the mold improves,so that the high quality skin can be formed. As a result, thecomplication of the manufacturing steps can be suppressed or avoidedwhile realizing the satisfactory sealed state between the adjacentsegments of the mold.

In the method of manufacturing the composite material structureconfigured as above, the composite material structure may include askeleton member in addition to the skin. The skeleton member may beattached to the outer peripheral surface of the mold, and the prepregmay be laminated on an outside of the skeleton member. A caul platecovering the prepreg may be attached to an outside of the prepreg.

In the method of manufacturing the composite material structureconfigured as above, a surface of the segment which surface constitutesan outer peripheral surface of the single structure may be referred toas a front surface of the segment. Both end portions of the seal groovemay be bent toward the front surface of the segment. A length of theseal member may be set such that when the seal member is inserted in theseal groove, end portions of the seal member are exposed from respectiveend portions of the seal groove, i.e., from the front surface of thesegment. After the seal member is inserted in the seal groove, the endportions of the seal member may be cut near the front surface of thesegment. End portion pressing members may be then fixed to the segmentand press the respective end portions of the seal member such that theend portions of the seal member are not exposed from the front surfaceof the segment.

In the method of manufacturing the composite material structureconfigured as above, after the end portions of the seal member are cutnear the front surface of the segment, the end portions of the sealmember may be covered with bonding members to be bonded to the frontsurface of the segment. The end portions of the seal members may be thenpressed by the respective end portion pressing members.

In the method of manufacturing the composite material structureconfigured as above, the plurality of segments may be fixed to a pair ofannular holding members to be kept as the single structure.

In the method of manufacturing the composite material structureconfigured as above, the plurality of segments may include: a segmenthaving the side surface on which the seal groove is provided; and asegment having the side surface on which the seal groove is notprovided.

In the method of manufacturing the composite material structureconfigured as above, a surface of the segment which surface constitutesan outer peripheral surface of the single structure may be referred toas a front surface of the segment. The segments may include two types ofsegments that are first segments each having such a shape that when thefirst segment is arranged horizontally with the front surface facingupward, each of both side surfaces of the first segment faces ahorizontal direction or a direction inclined upward relative to thehorizontal direction, and second segments each having such a shape thatwhen the second segment is arranged horizontally with the front surfacefacing upward, each of both side surfaces of the second segment faces adirection inclined downward relative to the horizontal direction. Thefirst segments and the second segments may be alternately arranged suchthat the second segments are first fixed at every other fixing positionsof the annular holding members, each of the first segments is insertedbetween the second segments, and the side surfaces of the first andsecond segments are coupled to each other. The seal grooves may beprovided only on the side surfaces of the first segments.

In the method of manufacturing the composite material structureconfigured as above, a plurality of concave portions into which skeletonmaterials are fitted may be formed on the front surfaces of the firstand second segments. The skeleton materials may be first attached to thefirst and second segments, and the first and second segments may be thenfixed to the annular holding members.

In the method of manufacturing the composite material structureconfigured as above, the lip portion may project in a normal directionof the seal upper portion or project so as to be inclined relative tothe normal direction of the seal upper portion. One of a width of theseal upper portion and a width of the seal bottom portion in a crosssection of the seal member may be larger than the other.

In the method of manufacturing the composite material structureconfigured as above, the concave portion may also be formed on the sealupper portion so as to be located close to the lip portion.

The present invention is not limited to the above embodiment, andvarious modifications may be made within the scope of the claims. Anembodiment obtained by suitably combining technical means disclosed indifferent embodiments and a plurality of modified examples is alsoincluded in the technical scope of the present invention.

From the foregoing explanation, many modifications and other embodimentsof the present invention are obvious to one skilled in the art.Therefore, the foregoing explanation should be interpreted only as anexample and is provided for the purpose of teaching the best mode forcarrying out the present invention to one skilled in the art. Thestructures and/or functional details may be substantially modifiedwithin the scope of the present invention.

INDUSTRIAL APPLICABILITY

The present invention is widely used in the fields of manufacturing alarge and substantially cylindrical composite material structure, suchas a fuselage of an aircraft.

REFERENCE SIGNS LIST

-   -   10 mold for manufacturing composite material structure (mold)    -   11 mandrel (single structure)    -   12 support ring (annular holding member)    -   17A, 17B mandrel (single structure)    -   20 first segment (segment)    -   21 segment front surface    -   22 segment end portion surface    -   23 segment side surface    -   24 segment end surface    -   25 seal groove    -   25 a outer seal groove (seal groove)    -   25 b inner seal groove (seal groove)    -   26 seal member    -   26 a first seal member (seal member)    -   26 b second seal member (seal member)    -   27 seal end portion pressing member (end portion pressing        member)    -   30 second segment (segment)    -   33 segment side surface    -   40 third segment    -   50 prepreg    -   51 caul plate    -   52 bagging film (vacuum bag)    -   53, 54 bonding member    -   261 seal main body    -   262 upright lip portion (lip portion)    -   263 hollow portion (inner hollow)    -   264 bottom surface concave portion (concave portion)    -   265 inclined lip portion (lip portion)    -   266 upper surface concave portion (concave portion)

1. A method of manufacturing a hollow composite material structureincluding a skin constituted by at least a thermosetting resincomposition and a fiber material, the method using a mold located in thehollow composite material structure, the mold being constituted by aplurality of segments and kept as a single structure by couplingadjacent side surfaces of the segments to each other, the methodcomprising: laminating a prepreg on an outer peripheral surface of themold, the prepreg being configured to become the skin by thermal curing;forming a vacuum bag after the prepreg is laminated, the vacuum bagbeing configured to seal an outside of the mold; and inserting sealmembers in seal grooves each provided on at least one of the adjacentside surfaces of the segments, each of the seal members being formed ina line shape having ends, wherein: a part of the seal member which partcontacts a bottom surface of the seal groove when the seal member isinserted in the seal groove is referred to as a seal bottom portion; apart of the seal member which part is opposed to the seal bottom portionis referred to as a seal upper portion; a lip portion is provided at theseal upper portion such that at least a tip end of the lip portionprojects to an outside of the seal groove when the seal member isinserted in the seal groove; the seal member is hollow therein orincludes a concave portion on at least the seal bottom portion of theseal member; and when assembling the segments as the single structure,the adjacent side surfaces of the segments are coupled to each other,and the seal member provided at one of the segments is crushed in across sectional direction by the side surface of the other segment toseal between the segments, the method further comprising whilesubjecting an inside of the vacuum bag to vacuum suction, subjecting theprepreg to the thermal curing while being pressurized by autoclaving ofthe entire mold.
 2. The method according to claim 1, wherein: thecomposite material structure includes a skeleton member in addition tothe skin; the skeleton member is attached to the outer peripheralsurface of the mold, and the prepreg is laminated on an outside of theskeleton member; and a caul plate covering the prepreg is attached to anoutside of the prepreg.
 3. The method according to claim 1, wherein: asurface of the segment which surface constitutes an outer peripheralsurface of the single structure is referred to as a front surface of thesegment; both end portions of the seal groove are bent toward the frontsurface of the segment; a length of the seal member is set such thatwhen the seal member is inserted in the seal groove, end portions of theseal member are exposed from respective end portions of the seal groove,i.e., from the front surface of the segment; after the seal member isinserted in the seal groove, the end portions of the seal member are cutnear the front surface of the segment; and end portion pressing membersare then fixed to the segment and press the respective end portions ofthe seal member such that the end portions of the seal member are notexposed from the front surface of the segment.
 4. The method accordingto claim 3, wherein: after the end portions of the seal member are cutnear the front surface of the segment, the end portions of the sealmember are covered with bonding members to be bonded to the frontsurface of the segment; and the end portions of the seal members arethen pressed by the respective end portion pressing members.
 5. Themethod according to claim 1, wherein the plurality of segments are fixedto a pair of annular holding members to be kept as the single structure.6. The method according to claim 5, wherein the plurality of segmentsinclude: a segment having the side surface on which the seal groove isprovided; and a segment having the side surface on which the seal grooveis not provided.
 7. The method according to claim 6, wherein: a surfaceof the segment which surface constitutes an outer peripheral surface ofthe single structure is referred to as a front surface of the segment;the segments includes two types of segments that are first segments eachhaving such a shape that when the first segment is arranged horizontallywith the front surface facing upward, each of both side surfaces of thefirst segment faces a horizontal direction or a direction inclinedupward relative to the horizontal direction, and second segments eachhaving such a shape that when the second segment is arrangedhorizontally with the front surface facing upward, each of both sidesurfaces of the second segment faces a direction inclined downwardrelative to the horizontal direction; the first segments and the secondsegments are alternately arranged such that the second segments arefirst fixed at every other fixing positions of the annular holdingmembers, each of the first segments is inserted between the secondsegments, and the side surfaces of the first and second segments arecoupled to each other; and the seal grooves are provided only on theside surfaces of the first segments.
 8. The method according to claim 7,wherein: a plurality of concave portions into which skeleton materialsare fitted are formed on the front surfaces of the first and secondsegments; and the skeleton materials are first attached to the first andsecond segments, and the first and second segments are then fixed to theannular holding members.
 9. The method according to claim 1, wherein:the lip portion projects in a normal direction of the seal upper portionor projects so as to be inclined relative to the normal direction of theseal upper portion; and one of a width of the seal upper portion and awidth of the seal bottom portion in a cross section of the seal memberis larger than the other.
 10. The method according to claim 1, whereinthe concave portion is also formed on the seal upper portion so as to belocated close to the lip portion.